Device for differential motion



Dec. 27, 1949- w KlMMlci-l DEVICE FOR DIFFERENTIAL MOTION Filed June 1, 1946 lNVENTOR m mmmum BY I ATTORN EY Patented Dec. 27, 1949 DEVICE FOR DIFFERENTIAL MOTION William Kimmich, Flushing, N. Y., assignor to Radio Corporation of America, a corporation of Delaware Application June 1, 1946, Serial No. 673,869

plextelegraph printers in equal but in opposite directions in order to place a local and received signal in the proper phase relation with respect to each other.

An object of this invention is to provide a simplified and improved device which will give differential motion for any mechanical or electrical equipment.

Briefly, this invention is an improved housing arrangement comprising two spaced end plates. Retained within the housing and supported by four. brackets are two moving gear assemblies, the outer gear assembly comprising two sectors of internal gears secured to a cylindrical sector and the inner gear assembly comprisin two external or spur sector gears which are also secured to another cylindrical sector. The sector gears are arranged so that they mesh with a small pinion having a shaft to rotate simultaneously each sector gear in an opposite direction. A brush holder is insulatingly secured to each of the two sector gears.

Prior to the conception of this invention, insofar as I know, there were no means to accomplish the displacement of the distributor brushes with respect to the commutator segments of the multiplex printer equipment. With this invention, it is possible to impart motion to the internal gear and external gear assemblies so that each brush is'displaced an equal distance but in an opposing direction, which greatly facilitates the operation of telegraph multiplex printers.

One specific use of the device of this invention is for a frequency correction unit for a seven unit code combination. In the operation of such a frequency correction unit, the frequency of the apparatus is operated at 42% cycles per second, which frequency permits the positive half of the printer equipment to be divided into seven equal units, and the negative half of the printer equipment to also be divided into seven equal units, making a total of fourteen combinations. This code combination, when multiplied by the 42 cycles, equals a total of 600 code impulses per second. It will be seen that with such a frequency and the large number of impulses, it will be absolutely necessary to have both the local and received signal in proper phase relation with respect to each other. Therefore, by connecting the brushes of the device of this invention with a suitable electronic frequency correction unit (which corrects the frequency of the local receiver by changing the bias on an electronic tube) it will be possible to bring both frequencies in exact alignment.

This invention will best be understood by refe'rring to the accompanying drawing, in which:

4 Claims. (01. 173-53) Fig. l is a plan view taken through the center between the two end plates;

Fig. 2 is a cross-section of Fig. l, the section being taken on lines 2-2;

Fig. 3 is a diagram of the device of this invention applied to a frequency correction unit; and

Fig. 4 is'a cross-section of Fig. 1, the section being taken on lines 4-4.

Referring now in detail to Figs. 1 and 2 of the drawing, a housing is shown havin two end plates I and IA, of insulation material, which are spaced parallelly by means of four metallic spacers 2 located in each corner of end plates I and IA, the spacers being secured by means of machine screws 2A. Retained within the two end plates and supported by four brackets 8 are two gear assemblies. The outer gear assembly comprises two sectors of internal gears 3 and 3A which are secured to a cylindrical sector 5 and fastened by means of machine screws 5A. The.

inner gear assembly comprises two spur sector gears 4 and 4A which are secured to a cylindrical sector 6 by means of machine screws 43. The internal and external sector gears are chosen and arranged to slide on brackets 8 so that they will mesh with a small pinion gear I which is provided with shaft IA, bearings 1B, 1C, and an operating knob ID, the knob being secured by means of a set screw IE. The brackets 8 are secured to panels I and IA by means of machine screws BA and positioned so that the gears 3, 3A,"

4 and 4A will move in equal but opposing directions.- In order that the gears will not become 7 detached from the brackets 8, stop pins 9 are provided at each end of the gears. In order to approach a uniform displacement, it is essential to choose as small a pinion gear and sector gears as possible. In order that the mechanical device of the invention may be used to shift the distributor brushes of multiplex telegraph printers, the cylindrical sectors ,5 and 6 are each provided with a brush holder which comprises a tubular housing member I 0 having located therein a cop-- per gauze brush I I, a brush cap I2, a brush tension spring I3, and an adjustable threaded stud I4. The tubular brush housing member ID is provided with an insulating tube I 5 which is secured to the central portion of each cylindrical sector. In order that the brush housing maybe free to move when the pinion gear! is rotated, open slots I5 and I1 are provided in the cylindrical sectors. The insulating tube is secured to the cylindrical sectors by means of aset screw I8. A flexible connection lead I9 is fastened to the upper portion of stud I4 and, is retained in position by means of suitable washers and nuts 20 and 2I. In order that the tension on brush I I may be adjusted, the upper portion of stud I4 is provided with'a screw driver slot 22. The insulating endplates I and IA are each provided with central 7 apertures 23 and 24 through which pass a rotary shaft which is arranged to rotate simultaneously withlthe multiplex printer equipment. An insulating disc 26 is secured to shaft 25 by means of a set screw 21. insulating disc 26 has located thereon two semicircular collector rings 28 and "ZQWhiCh are secured to the disc by means. of. small flat head screws 30; or, if desired, the rings Hand 29 may be molded directly into position by making disc 26 of molded insulating material.

In the operation of this device, as theshaft'of pinion 1 is rotated in its bearings by the-:operation of knob ID, it imparts motion to the internal andspur gear brush holder assembly. Thedirection of displacementof each brush holder, how

ever, is opposite, and the travel equal, as willbe noted when points A and B are observed with.

respect to the pinion axis or a center reference point C. The distributor brushes ll are.ele.c-.

tric'ally connectedto any suitable means, such as a frequency correction unit shown in Fig. 3,.

which places the local andfreceived signalsin proper phase relation with respect to each other before they enter the multiplex printer mechanism. The device of this invention is.no.t limited. in its use :to; multiplex printer mechanism as it maybe appliedto any other equipment.

Whatis claimed is: 1. A device for shifting the distributorbrushes,

ofmultiplex telegraph printers in equal amounts but opposite directions, in order to place a local. and received signal improper phase relationwith respect to each other, comprising a frequency correcting unit for saidreceivedlsignal, a housing member, arotatable shaft arranged. to rotate simultaneously with amultiplex telegraph printer, two concentrically spaced gears each having teeth which face each other, said gears being. arranged.

to' rotate within said housing member, an operating shaft, having bearings. within said housing, member, a pinion gear secured-to said'shaft and positioned'to mesh with the teeth of each gear,

insulating support means secured to each. gear, a brush member securedto said insulating support means, a metallic collector ring, saidfring:

being divided into two equal halves and insulatingly arranged on said rotatable shaft to.

rotateconcentrically, within said spaced gears-to contact said brushes, and means; to' electrically connectsaid brushes through said collector ring with said frequency correction unit'of a multiplex telegraph printer;

2; In a multiplex printer of thetype having a; distributor provid'edwith two angularly disposed distributor brushes, means for shifting the relative'positions of said brushes'in equal but in oppositedirections, said means including two par'-- allelly'spaced plates, a rotatable shaft arranged toextend within the space between said parallelly spaced plates and linked with the mutiplexprinter, an insulating disc secured forrotation with said-"shaft, a metallic collector ring, located on. the outerperiphery of'said insulating disc-and engaging said distributor brushes, said ring being divided into-two equal halves, an operating shaft;

a pinion gear secured'to an endof said operating shaft, inner and outer arcuategears coaxiallyarrangedito'rotate between said parallelly spaced plates,- insulating means to secure each-of said" brushes to said inner and outer 'arcuate gears; a gear-support to space each gear in anoperative position within said spaced plates; is'ai'd pinion being positioned to mesh with the teethsof" saids'paced arcuategears whereby motion whichisnapplied to: said operating shaft will. move the The outer periphery of the:

file of'this patent:

UNITED STATES PATENTS Number Name Date- 1,742,957 Hull Jan. 7, 1930 2,374,295. Mathes Apr. 24,1945".

4 gears in equal but in opposite directions to change theposition of said brushes with respect to said pinion gear.

3. In a multiplex printer of the type having a distriblltor. provided with two angularly disa pinion gear secured to an end of said operating;

shaft, a plurality of inner and outer spaced areas,- ate. gears'coaxially arranged in pairs to rotate between said parallelly means to secure each of and-outerspaced arcuategears of each pair; each gear support having a slot to permit the passage; ofabrush which issecured to an oppositelylocated arcuate gear, a gear suport to space each: gearofteach pair in an operative positionwithin said-spaced plates, said pinion gear being posh.

tioned to mesh with the teeth of said spaced arcu-y ate gears whereby motion is applied to said open--v atingshaft will move the gears of each pair in,

equal butin opposite directions to'change the position of said brushes with respect to said pinion gear.

4; In amultiplexprinter of the type-having'ax two angularly disposed. distributor brushes, means for shifting;the-rela.--

distributor provided with tive positions of said brushes in equalbutin oppoe Site, directions, said means including two par-J allelly spaced plates, a plurality of spacing-mum bers. for spacing said plates, means for binding said spacing members rotate simultaneously with a multiplex; printer,

an insulating'disc secured for rotation with'sa-idw shaft, a. metallic collector ring located; onthe. outer periphery of said insulating disc and=posie tioned to make contact with said distributor: divided into two equal;

brushes, said ring being halves, an operating shaft, a pinion gear secured to" an end of said operating shaft, a plurality ofinner and outer spaced each of said eachgear of each pair in an operative position within said spaced plates, said pinion gear being positioned to mesh with the teeth of said spaced-- arcuate gears whereby motion which is applied .to. move thegears of each; pair. -inequal but in opposite directions to change.- the position of said brushes with respectto saidl said operating shaft will pinion gear.

WILLIAM REFERENCES CITED The following references are of record-in the spaced plates, insulating said brushes to said-inner to said plates; a rotatable shaft arrangedto. extend within thespace be; tween said parallelly spaced plates and linkedto.

arcuate gears arranged,- coaxially in pairs to rotate between said par-- allelly spaced plates, insulating means to SBCllIe-c brushes-to said inner and outer a-rcu ate gears-of each pair, a gear support to space- 

